Well head assembly for petroleum wells



Dec. 11, 1962 w. G. GREEN WELL HEAD ASSEMBLY FOR PETROLEUM WELLSINVENTOR. W. a. GREEN i llll.

E Z4 M 9.

AGENT United States Patent Office 3,067,820 Patented Dec. 11, 19623,067,820 WELL HEAD ASSEMBLY FOR PETROLEUM WELLS William G. Green,Tulsa, Okla, assignor, by direct and mesne assignments, to AquatronEngineering Corp, St. Petersburg, Fla, a corporation of Florida FiledJuly 23, 1958, Ser. No. 750,359 2 Claims. (Cl. 166-88) This inventionrelates to the physical construction of an improved oil Well headassembly.

A variety of well head assemblies have heretofore been proposed,illustrative of which is that set forth in Patent No. 2,082,107 grantedto James H. Howard on June 1, 1937. Such assemblies have, however, beencomplex in design, expensive and in many instances difficult toassemble.

It is therefore one general object of this invention to improve wellheads.

Another object is to provide an extremely simple and yet exceedinglyeffective well head which is economical, rugged in construction anddurable in performance.

Yet another object of this invention is to provide a unique locking ofcertain of the well head elements thereby to increase safety and preventfailure due to blowouts or other causes.

Still another object of this invention is to provide in a well headassembly, members which both automatically center and lock in assemblythe various concentric members which are conventional to an oil wellbore.

A further object is to provide electrical insulation between the oilwell tubing and easing, thereby to permit I electrical measurement of avariety of electrical pheno-mena.

Accordingly, in accordance with one feature of the invention, a simpleyet rugged tapered steel plug is mounted upon the well surface pipe, thecasing pipe is inserted therethrough, and a plurality of steel balls aresuitably disposed circumferentially between the outer surface of thepipe and the inner tapered surface of the plug, thereby automaticallycentering the casing within the surface pipe.

In accordance with another feature of this invention, an additional plugis arranged to cooperatively mate with the tapered steel plug whereby,when the additional plug is screwed into the tapered plug, a downwardthrust is applied to the steel balls to move them down along the taperedsurface and force them into the pipe wall, thereby locking the pipe,balls and plugs together into one fixed assembly.

In accordance with yet another feature of the invention, the string oftubing within the casing is locked to the casing by a somewhat similarassembly, the tapered plug, however, being made of a suitable insulatingsubstance such as Mi-carta or Formica and having a tapered annularhardened steel ring for cooperative association with the aforementionedsteel balls. Thus, the well pipe string is electrically insulated fromthe surface pipe and well casing.

In accordance with still a further feature of the invention, acylindrical ring is snugly fitted about the pipe in each of the twoassemblies at a point just below the location of the steel balls toprevent any substantial vertical movement of the pipe in the event thepartial embedding of the balls themselves in the pipe walls should failto hold the pipe in position, thereby greatly enhancing the safety ofthe assemblies.

In accordance with another feature of the invention, the cylindricalring is so related to the surrounding dimensions that it will, when thetubing is lifted up, raise the balls to a position of easy removal andprevent their dropping into the well bore.

These and other objects and features of the invention will be apparentfrom the following detailed description,

by way of example, with reference to the drawing in which the singleFIGURE depicts the vertical section of a Well head constructed inaccordance with the principles underlying the invention.

It will be seen therein that in the earth 4 there is a conventional T 2which is mounted upon the upper end of an oil well surface pipe 3. Pipe3 is suitably anchored in concrete (not shown) and T 2 provides a meansof access through opening 5 to the space intermediate the surface pipe 3and the casing 6. Snugly fitted upon casing 6 is a safety ring 7 whichmay be secured to casing 6 by set screws 8 (as shown) or by othersuitable means such as shrink fitting. The purpose of this ring and thefunction performed by it are hereinafter more particularly set forthbelow.

Screwed into T 2 is tapered sleel plug 9 which is equipped with mountingthreads 10 about its lower outer periphery and with a hardened taperedsurface 11 about its lower inner surface, the smallest inside diameterof plug 9 being greater than the outer diameter of ring 7 in order toallow the ring to project up past the lower end of plug 9 as depicted.

In the space intermediate the plug and the casing are a plurality ofsteel or other suitably hardened balls 12 which, when forced down by theinclined surface 13 of inner plug 14, move longitudinally down along thepipe and tapered surface 11. Since the available space decreases due tothe taper, and since the balls and tapered surface are harder than thewall of the pipe, the pipe wall will deform as the balls dig therein,thus locking the various cooperating members 6, 9, 12 and 14 together.

The ring or sleeve 7 is suitably secured to casing 6 at a point slightlybelow the point the balls will occupy at the end of their travel. Itserves to prevent any substantial upward movement of the casing withrespect to the remaining members in the event of abnormal conditionssuch as an unexpected increase in well pressure, etc. The ring thus actsas a back-up safety device in the event forces tending to upwardlydisplace the casing should exceed those for which the ball lockingassembly is designed.

The remainder of the elements depicted below the reference line 15 areconventional. Thus, for example, suitable compression seals 16 areprovided to prevent the escape of well products from the spaceintermediate the.

casing and surface pipe.

Now turning to that part of the drawing above the reference line, itwill be noted that depicted there is a somewhat similar locking assemblywhich serves to lock the inner tubing 17 to the casing 6. Certaindifferences exist, however, between the upper and lower lockingassemblies. Thus, in the upper assembly, for example, the one-piececross 18 replaces the T 2. Another difference lies in the material andconstruction of the tapered plug 19 which corresponds to plug 9 to thelower joint.

Plug 19 is made of some suitable insulating material such as Formica orMicarta. It is suitably threaded, and is milled to receive a taperedsteel ring 20 which is hardened in order to provide the desired bearingsurface.

In all other respects, the upper assembly corresponds to its lowercounterpart.

Angles 21 and 22 may be welded to cross 18 and coupling 23 in order toprovide a convenient means of making independent electrical connectionsto the casing and inner tubing wherever desired and particularly for thepurposes shown in my copending application Serial No. 655,406 filed Apr.26, 1957, entitled Paraffin Removing Device as well as for other uses.

The method of assembly of both joints is similar. First, the T or crossis screwed upon its mounting pipe, i.e., the surface pipe or the casing.Next the tapered plug is installed and the pipe which is to be securedis inserted in such manner that the outer ring (7 in the lower joint) ispositioned just below the termnial position of the balls. Next, theballs are placed in the positions shown peripherally about the taperedsurface and the outer wall of the pipe. By moving all of the ballsdownward along the taper to the same corresponding positions while atthe same time permitting transverse movement of the pipe, the pipe willbe automatically centered within the tapered plug.

Locking plug (14 in the lower figure) is next inserted and is screwedfarther and farther into the tapered plug. As its lower inclined surface13 impinges upon the balls 12, it forces them down along the taperedsurface 11. Being squeezed between the tapered surface and the wall ofthe pipe, they begin to deform the pipe wall and partly imbed themselvestherein as indicated at 24. After they have thus deformed the pipe wallthe desired amount, movement of the locking plug is stopped and theassembly is complete.

Although I have illustrated my invention by one particular illustrativeembodiment thereof, the invention is not limited in its application tothe specific apparatus and particular arrangement therein disclosed.Various applications, modifications and arrangements of the inventionwill readily occur to those skilled in the art.

What is claimed is:

1. Apparatus comprising a first pipe, a plug defining a tapered openingtherethrough mounted upon said first pipe, a second pipe within saidfirst pipe and extending through said tapered opening, said second pipecoextending with said first pipe to form an annular space between saidpipes and substantially closed at one end by said plug, a plurality ofballs disposed peripherally about said second pipe and in contact withthe tapered surface of said opening and with the outer surface of saidsecond pipe, a sleeve mounted upon said second pipe at a point slightlybelow the point at which said balls contact said second pipe, saidsleeve being of slightly smaller outside diameter than the smallestinside diameter of said tapered plug, and means for forcing said ballslongitudinally along said tapered surface and said second pipe therebyto force said balls partly into the wall of said second pipe at a pointimmediately adjacent the end of said sleeve and lock said first pipe,said plug, said balls and said second pipe together.

2. Apparatus comprising a first pipe, an insulating plug defining anopening therethrough mounted upon said first pipe, a hardened membermounted within said opening and having peripheral contact with the innersurface of said plug, said hardened member having a tapered innersurface therethrough, a second pipe within said first pipe and extendingthrough said tapered member, said second pipe coextending with saidfirst pipe to form an annular space between said pipes and substantiallyclosed at one end by said plug, a plurality of balls disposedperipherally about said second pipe and in contact with the taperedsurface of said member and with the outer surface of said second pipe, asleeve mounted upon said second pipe at a point slightly below the pointat which said balls contact said second pipe, said sleeve being ofslightly smaller outerside diameter than the smallest inside diameter ofsaid hardened member, and means for forcing said balls longitudinallyalong the tapered surface'of said hardened member and said second pipethereby to force said balls partly into the wall of said second pipe andlock said first pipe, said plug and hardened member, said balls and saidsecond pipe together.

References Cited in the file of this patent UNITED STATES PATENTS Re.19,910 Parker Mar. 31, 1936 1,036,547 Bell Aug. 27, 1912 1,337,288Strichler Apr. 20, 1920 1,932,570 Black Oct. 31, 1933 2,182,797 DillonDec. 12, 1939 2,728,396 Carpenter Dec. 27, 1955 2,757,738 Ritchey Aug.7, 1956 2,809,699 Battle Oct. 15, 1957 2,812,818 Brusco Nov. 12, 1957

